Infusor drive means

ABSTRACT

An infusor apparatus for a coffee brewing machine has a cam driven piston means. The cam has appropriate dwells formed thereon to interrupt the travel of the piston means during the compression stroke approximately halfway along the stroke and again at the completion thereof, in order to relieve the pressure within the chamber during and after brewing so that infusible or brewed material will not be blown from the chamber when it is suddenly opened after brewing is completed.

United States Patent 1191 1111 3,754,462 Brill Aug. 28, 1973 INFUSORDRIVE MEANS 2,387,871 10/1945 Baumann 99/302 P 2,667,114 1/1954 Burgess[751 Invent: Frank 3"" Nmndge, 2,827,845 3/1958 Richeson 99/287 x [73]Assignee: The Seeburg Corporaton of Delaware, g Pn'mqry Examiner-WayneA. Morse, Jr. [22] Filed, Sept 28 1971 Attorney- Ronald L. EngeLJames M.Amend et a1.

l A l. N 84499 [2 1 pp 1 57 ABSTRACT [52] Us. Cl I 99/287 99/289 99/297An infusor apparatus for a coffee brewing machine has 99/3o2 a camdriven piston means. The cam has appropriate [5 1 In. CL. dwells formedthereon to interrupt-the travel of the [58] Field of Search 99/287, 289,292, means the aPPmX" 99/297 302 P mately halfway along the stroke andagain at the completion thereof, in order to relieve the pressure withinthe chamber during and after brewing so that infusible [56] or brewedmaterial will not be blown from the chamber when it is suddenly openedafter brewing'is completed. 3,682,090 8/1972 Men'ggi 99/289 3,413,90712/1968 Schwertfeger 99/287 1 Claim, 4 Drawing Figures INFUSOR DRIVEMEANS PATENT INCORPORATED BY REFERENCE The subject invention comprisesan improvement upon the infusor Apparatus which is fully described inthe patent issued to 0.]. Schwertfeger et al. on Dec. 3, 1968, US. Pat.No. 3,413,907 (copy submitted herewith), the disclosure of which isincorporated herein by reference for the purpose of placing the instantinvention in its proper context. The reference numerals utilized in U.S.Pat. No. 3,413,907 have been carried over to the instant application,where possible, for convenience and to promote clarity of reference, andadditional reference numerals have been added in the instantspecification to point out particularly the improved features comprisingthe subject invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The subjectinvention relates to the infusor art, and more particularly thisinvention relates to an improvement in the control of the brewing cycleof a coffee brewer and vendor.

2. Description of the Prior Art The most pertinent prior art referenceis the Schwertfeger et al. patent which is incorporated by referenceherein. That patent discloses an improved one cup coffee brewer anddispenser comprising a brewing chamber having a coffee outlet openingand filter means adapted to operate in conjunction therewith. In thatdevice, which itself represented a significant advance in the infusorapparatus art, means were provided for: (l) placing a charge of groundcoffee in the brewing chamber; (2) sealing the ground coffee therein;and (3) injecting a jet stream of hot water into the ground coffee so asto cause vigorous agitation thereof. Simultaneous with the influx of hotwater, pressurizing means in the form of a piston were adapted toincrease the pressure within the brewing chamber so that the groundcoffee was rapidly and thoroughly infused with the heated water. Theresulting brewed coffee was discharged from an outlet opening in thechamber through suitable filter means, said filter means also beingadapted to dispose of the coffee grounds after brewing was completed.

Inherent in the device of the Schwertfeger et al. patent, and in otherprior art infusor apparatus which require the pressurization of thebrewing chamber, is the problem of fouling of the mechanisms containedtherein by spent coffee grounds or other infusible material. Insituations wherein the pressure in the brewing chamber was not fullyreleased prior to the opening of the brewing chamber immediatelyfollowing brewing completion, which frequently occurred, the resultantrush of compressed air from the chamber blew spent grounds about theinterior of the apparatus before said grounds could be disposed ofproperly.

The foregoing problem was exacerbated when soft water was used inbrewing. Soft water causes coffee grounds and the like to swell to amuch greater extent than does hard water, thus inhibiting the passage ofboth compressed air and brewed coffee through these grounds to theoutlet. In such instances the full charge of brewed coffee frequentlywas not expelled from the brewing chamber, nor was the pressure in thechamber fully relieved before the chamber was opened. The result wasthat brewed coffee and coffee grounds were blown about the infusordevice upon the chamber's being opened.

And regardless of the type of water used in brewing, difficulty was alsoencountered in connection with prior art infusor devices when thebrewing of larger cups of coffee than originally contemplated for thedesign of a given device was attempted. When timed for the brewing ofsmaller cups of coffee, an insufficient SUMMARY OF THE INVENTION Inorder to overcome the above-described disadvantages which inhere ininfusor brewing devices in which the brewing chamber is pressurized bypressurizing means in the form of a piston which steadily decreases thevolume therewithin (as in the apparatus described in the Schwertfeger etal. patent and most other prior art devices), the subject invention isadapted to permit the periodic release of pressure within the brewingchamber during the brewing operation and the com} plete brewing oflarger-than-normal batches. To this end the subject invention comprisesa cam with appropriate dwells adapted to drive the piston means in sucha manner so as to convert the uninterrupted piston compression stroke ofthe prior art devices into an intermittent stroke and to provide for thepistons remaining stationary at the completion of its compression strokefor a period of time before the brewing chamber is opened.

More specifically, the device disclosed in the Schwertfeger et al patentemployed a cam which causes a steady travel of the piston throughout itscompression stroke by means of a pivotable spring-biased lever. Im-

'mediately upon the completion of the compression stroke the bias on thelever caused the piston to be withdrawn from the brewing chamber. Incontrast to this arrangement, the cam comprising the subject inventionis provided with two dwells. The rotary motion of this improved cam istranslated by the same lever linkage utilized in the Schwertfeger et aldevice into an intermittent piston compression stroke, having pauses atapproximately the middle and end of the said stroke. The first dwellportion of the subject cam is designed to produce a pause ofapproximately 1.0 second at the halfway point, and insures that adequatetime is allowed for complete brewing of the coffee, regardless of thebatch size, and prevents the expulsion of underbrewed coffee from thebrewing chamber. The second dwell causes a pause of approximately 2.0seconds duration after completion of the compression stroke and beforethe brewing chamber is opened, thus insuring equalization of thepressure within the brewing chamber with that of the external chamberenvironment and obviating the problem of the apparatus being fouled bycoffee grounds and/or non-dispensed brewed coffee being blown from thechamber by the sudden exit of compressed air when the chamber is opened.The improved cam comprising the subject invention thus substantiallyeliminates problems long associated with piston-type brewing devices,and is of particular advantage where soft-water and/or relativelylarge-sized cup brewing is attempted.

Accordingly, a primary object of the subject invention is to improveinfusor brewing devices, and to prevent them from being fouled by theexpulsion of coffee grounds or non-dispensed brewed coffee from thebrewing chamber at the end of the brewing cycle.

It is another object of the subject invention to improve the quality ofcoffee or the like produced by infusor brewing devices.

It is a still further object of the subject invention to improve theoperation of infusor brewing devices when soft water is used as abrewing media therein.

It is yet a further object of the subject invention to improve theoperation of infusor brewing devices by permitting them to brew largerbatches of infusible material than was originally intended, whilemaintaining the high quality of the resultant product.

DESCRIPTION OF THE DRAWING FIG. 1 is a schematic view of an embodimentof an infusor drive means in accordance with the present invention,showing the first step of the brewing cycle.

FIG. 2 is a schematic view of the drive means shown in FIG. 1 at a laterpoint in the brewing cycle, in which the piston is in a first restposition.

FIG. 3 is a schematic view of the drive means shown in FIG. 1 at the endof the brewing cycle, in which the piston is in a second rest position.

FIG. 4 is a schematic view of the drive means shown in FIG. 1 in itsnormally biased position following the end of the brewing cycle.

DESCRIPTION OF THE PREFERRED EMBODIMENT As mentioned hereinbefore, theimproved infusor drive means of the subject invention is adapted for incorporation into the Infusor Apparatus described in detail in the patentto Schwertfeger et al. US. Pat. No. 3,413,907, the disclosure of whichis incorporated herein by reference. Except for the inventiveimprovement in the drive means described herein, the operation andconstruction of the infusor apparatus is precisely as described in theSchwertfeger et al. patent, and a description of the portions thereofnot relevant to the subject improvement will not be repeated herein.FIG. 2 of the patent to Schwertfeger et al shows the prior artconstruction which the subject invention is designed to improve andreplace, and a comparison of that FIGURE with the drawing in the presentapplication will clearly indicate the context of the present in vention.The reference numerals in FIG. 2 of the Schwertfeger et al referencehave been carried over to the present drawing, where possible, tofacilitate this means 242 and more specifically, piston 50 which isfixedly mounted on a piston shaft 51 in a conventional manner. Piston 50is adapted to be driven reciprocably between the positions schematicallyshown in FIGS. 14, with part of its travel taking place within chamber41. Chute spout 71 provides a means by which a brewing charge ofinfusible material such as coffee or the like may be introduced intobrewing chamber 41.

Unitary drive assembly 31 is adapted to drive piston 50 in a mannerhereinafter described and comprises cam means 248. A drive cam 250(which differs from cam 144 in the Schwertfeger et al patent) is mountedon cam shaft 143 and comprises a novel piston drive profile 251(designated at various points by reference characters 251A, 2518, 251C,251D and 186, the significance of which will hereinafter appear) and achamber drive profile (not shown, but identicalto chamber drive profile146 in the Schwertfeger et al patent). Drive assembly 31 furthercomprises a pair of L-shaped arms 170, which are pivoted about a pivotshaft 171 and are separated by a spacer 172 also mounted on shaft 171. Aroller 173 is rotatable between the upper ends of L-shaped arms about apivot shaft 174, and is adapted to move in a slot 175 (shown in brokenlines in FIG. 1) as piston shaft 51 slides downwardly. A spring 175A isstretched between a pin 176 which passes between brackets 177 onL-shaped arms 170 and a bracket attached to the frame of theSchwertfeger apparatus (not shown), thereby urging L-shaped arms 170toward their normally biased positions shown in FIG. 4.

A spring-loaded roller-follower 180 is mounted between the lower end ofL-shaped arms 170, and rollerfollower 180 is adapted to contact andengage cam profile 251 on cam 250. Roller-follower 180 rotates about apivot shaft 181, the ends of which are rotatably journaled in a pair ofspring-pushing brackets 182. A slot 183 (shown in broken lines inFIG. 1) is provided in each lower end of L-shaped arms 170 in a mannersuch that the pivot shaft 181 is slideable between a lowered and raisedposition. A pair of springs 184 are respectively held in a pair ofspring-retaining members 185 fixed to each lower end of L-shaped arms170, and springs 184 urge brackets 182 downwardly. The purpose forspring loading roller-follower 180 will hereinafter appear.

As cam 250 rotates in a clockwise direction (as shown by the arrow inFIG. 1) cam profile 251 acts against roller-follower 180, therebycausing L-shaped arms 170 to initially pivot in a counterclockwisedirection about shaft 171. This in turn causes piston 50 to be drivendownwardly (e.g., from the position shown in FIG. 1 to that shown inFIG. 2) by roller 173 disposed in slot 175 of piston shaft 51, piston 50being maintained in alignment by means of bearing guides (not shown)which control the downward sliding movement thereof.

In the actual operating sequence, as cam 250 rotates in a clockwisedirection from its normally biased position shown in FIG. 4 to theposition shown in FIG. 1, piston 50 is correspondingly raised from theposition shown in the former FIGURE to that shown in the latter. Whenpiston 50 is in the FIG. 1 position infusible material is introducedinto chamber 41 through chute spout 71. Thereafter, as cam 250 continuesto rotate, roller-follower 180 traverses cam shaft 143 and reaches thefirst rise of cam profile 2S1 indicated by the portion of cam profile251 included between points designated by reference numerals 251A and2513. By means of the above-described unitary drive means 31, thistraversal results in the movement of piston 50 from the position shownin FIG. 1 to that shown in FIG. 2. After traversing this rise,roller-follower 180 encounters a first dwell portion on cam profile 251,which includes that portion of the profile located between pointsdesignated by reference characters 251B and 251C. As this dwell portionis traversed, piston 50 remains substantially motionless in a first restposition for approximately 1.0 seconds, at a point approximately halfwayalong its total distance of downward travel, or compression stroke. FIG.2 indicates the position of piston 50 and relevant parts of the unitarydrive assembly 31 during this portion of the cam rotation cycle.

After traversing first dwell portion 251B251C, roller-follower 180encounters a second rise on cam profile 251, which occupies the portionof said profile included between points designated by reference numerals251C and 251D. During the traversal of this rise, piston 50 is drivenfrom the position shown in FIG. 2 to that shown in FIG. 3, the latterbeing its lowest point of travel, and corresponding to the end of thecompression stroke. The position of piston 50 shown in FIG. 3, itssecond rest position, is maintained for a period of approximately 2.0seconds as roller-follower 180 traverses the second dwell portion of camprofile 251, which includes the portion of said profile between pointsdesignated by reference numerals 251D and 186.

As roller-follower 180 reaches the return portion of cam profile 251,beginning at the point indicated by reference character 186, spring 175Acauses clockwise movement of L-shaped anns 170 and pulls piston shaft 51and piston 50 upwardly, back to their normally biased positions shown inFIG. 4.

Roller-follower 180 is spring loaded, as previously described, so as torelease any stress which develops within drive assembly 31 as cam 250rotates. Thus as roller-follower 180 passes over the return portion ofcam profile 251 it is pushed upwardly into slot 183 against the bias ofspring 184.

As discussed hereinbefore, the novel improvement in drive assembly 31described above greatly enhances the dependability and capability of theinfusor apparatus in which it is designed to be incorporated. The firstdwell portion on cam 250, designated on cam profile 251 by referencenumerals 25lB-2SIC, results in piston 50 maintaining a first restposition for approximately 1.0 second (FIG. 2) at a point halfway alongits compression stroke. This provides an opportunity for more completebrewing of the infusible material introduced into chamber 41 throughchute spout 71, and is particularly advantageous in connection with thebrewing of large batches of coffee or the like. By permitting use of thesame infusor apparatus for the brewing of various sized portions of thebeverage to be dispensed, this novel feature provides a significantimprovement over prior art devices.

Furthermore, the second dwell portion on cam 250, designated on camprofile 251 by reference numerals 251D-186 prevents any liquid orremnants of infusible material (e.g., coffee grounds or the like)remaining in chamber 41 after brewing is completed from being blown outof chamber 41 when piston 50 is withdrawn from the chamber (FIG. 4). Thesecond dwell portion permits piston 50 to remain in a second restposition (FIG. 3) for about 2.0 seconds, during which time any pressurewithin chamber 41, built up during the compression stroke of piston 50,can be released. This is particularly important in connection withsoft-water brewing, wherein normal pressure dissipation through thebottom of chamber 41 is impeded by the swelling of the infusiblematerial within the chamber.

Thus, the subject invention provides a unique method for increasing theversatility and dependability of operation of an infusor apparatus suchas that shown in the Schwertfeger et al. patent. Not only is thepossibility of the fouling of such an apparatus during normal operationsubstantially eliminated, but the subject invention allows such anapparatus to be used in brewing large cups of coffee and the like and inoperations where soft water is employed as a brewing media.

Obviously, many other modifications and variations of the presentinvention are possible. It is to be understood that the inventiondescribed in this application is not limited to the details ofconstruction and arrangement of parts specifically described orillustrated. It should further be understood that various changes,modifications and alterations may be effected in the parts and elementsin the described embodiment without departing from the spirit and scopeof the present invention, as described in the appended claims.

I claim:

1. In an infusor apparatus for brewing coffee and the like comprising abrewing chamber in which infusible material and a liquid jet stream arecombined and comprising reciprocable piston means to decrease the volumewithin the brewing chamber, an improvement in the drive means toactivate said piston means comprising:

cam means having at least two dwell portions,

wherein said first dwell portion causes the travel of said piston meansto be interrupted intermediate the ends of its compression stroke for asufiicient time to permit the completion of the brewing of the infusiblematerial; and wherein said second dwell portion causes the travel ofthepiston means to be interrupted at the end of its compression strokeand before the initiation of its exhaust stroke for a sufficient time topermit the pressurized liquid to be expelled from the the bottom of thechamber and to permit the pressure built-up within said brewing chamberto be dissipated through the bottom of the brewing chamber until thepressure within the chamber is equalized with the ambient pressure.

1. In an infusor apparatus for brewing coffee and the like comprising abrewing chamber in which infusible material and a liquid jet stream arecombined and comprising reciprocable piston means to decrease the volumewithin the brewing chamber, an improvement in the drive means toactivate said piston means comprising: cam means having at least twodwell portions, wherein said first dwell portion causes the travel ofsaid piston means to be interrupted intermediate the ends of itscompression stroke for a sufficient time to permit the completion of thebreWing of the infusible material; and wherein said second dwell portioncauses the travel of the piston means to be interrupted at the end ofits compression stroke and before the initiation of its exhaust strokefor a sufficient time to permit the pressurized liquid to be expelledfrom the the bottom of the chamber and to permit the pressure built-upwithin said brewing chamber to be dissipated through the bottom of thebrewing chamber until the pressure within the chamber is equalized withthe ambient pressure.